1.About the DLC Add-On from PlaystationStore, i cant seem to make this work.I download the free ones. Theres a material set pack, Colour Variation pack etc.Now it works to download them just fine, but thats all there is to it.They dont show up in the "tools for gamedata" section (where all other dlc appear in, once downloaded)

2.Are the trophies everyone talks about the titles in-game?Because i cant seem to even find the game in the little list, in my Playstation 3 Trophies Section on my account.Could it be possible that it first appears after unlocking the first one?

Haven't played the game yet but in Tales of Graces:f you access DLC data by unwrapping it in your item menu in the actual game. So you might look through like Misc. items or something and see if there's any DLC to unlock. Some DLC weren't available until a certain story point, even if you'd already purchased them.

To get the DLC in XIllia is the same as Graces. Just go to your in game menu, and go all the way over to the right. Click on the DLC, it will tell you what the package includes, and you just need to select unwrap.

For the trophies, they appeared for me right after I inserted the game? Maybe try to connect to the internet? Idk, but yeah, all the trophies are different titles that give you grade.